From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A49CF3E51F5; Mon, 12 Oct 2026 14:55:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791816902; cv=none; b=PIHFJSc1TkCEVVYIgCaxmB2HT0wzG4RMqrfsg6i0ydzOZtphre7vAoBBx4d1Wxxp8rmlLrhd2ISvkW19WHGNdkl4W23LglGUqWcMk927CufIt7Z7axfURuCa2UidhtsZG5QQpsoj1y+jeRcHZWhkuuAMd1Qh4puxx/isxtpKIXQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791816902; c=relaxed/simple; bh=OrVEu59gq2n54Nhmry3hSQCdx5t9FmndTbxVrh4n+O4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YTpJO3ir6OTiUXd71uiGCnGql6qe9jKTickDA/4muDAdynzteYNJuWuYfg5OX53iCr6Vsjpouh44lPGF8UiaG9fXlx37acIie06FlYoPkO3SvTsZVw4xun24cE6LNEpO1JWqf1/QXzhlNbgC8NxvhVAFi/G3ECcNJLA0TGNf3As= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JykU3ZWX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JykU3ZWX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B64D71F0089C; Mon, 12 Oct 2026 14:54:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791816901; bh=HjF+dwN8jkIOmYUrrmNbDo0OkbvjjoMsq7uNZRAJ+PE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=JykU3ZWXRY0rwTALJyGgXe4AGmqAVnSamo0Y0VhNMkc/GCU9qZFvaDUEBs2/cKC/p dsbl6OV4fT0F49vsIbtpg9+ra+kkAmr9uyMQT/EUuWKgL6FqfLqrLPgqbYYHc4dnUN kJUa6PsO0uC+bcM16SyQA/dozU9b5DKf30owY10v0kWvWmFjdAHOKMH8MMbUFeYSJV htdsBAl1+wPY+s4xvC7AHkzLtwW8PjPEwqj+arJ4A6YJYdduYCgV7kfSenMjbWBict kRD00j0YobueSZYk3+udbYH+3I86iUjdvLfkG39iRIrdfqwP/BxyHl9PgJWJhYpbP4 +Ge3UKzf9+Svw== Message-ID: <96f4dc4d-eb5c-4af2-86e4-8d10f87b3d9d@kernel.org> Date: Mon, 12 Oct 2026 16:54:57 +0200 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5] ACPI: video: force native backlight on Dell OptiPlex AIO 7410 35W To: chitranshmandhaniya@gmail.com, ilpo.jarvinen@linux.intel.com, rafael@kernel.org Cc: lenb@kernel.org, platform-driver-x86@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Chitransh_Mandhaniya@dell.com References: <20261009072401.52509-1-chitranshmandhaniya@gmail.com> <20261010124830.116750-1-chitranshmandhaniya@gmail.com> From: Hans de Goede Content-Language: en-US, nl In-Reply-To: <20261010124830.116750-1-chitranshmandhaniya@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi, On 10-Oct-26 14:48, chitranshmandhaniya@gmail.com wrote: > From: Chitransh Mandhaniya > > The Dell OptiPlex AIO 7410 35W (board 01KP8D) declares DELL0501 in its > ACPI DSDT (status = 0x0F) even though no UART scalar board is physically > present. This causes acpi_video_get_backlight_type() to return > acpi_backlight_dell_uart, which makes i915 skip registering > intel_backlight. The dell-uart-backlight driver then times out talking > to the absent board and the probe fails, leaving the machine with zero > backlight control. > > A BIOS update fixes this on some models (e.g. OptiPlex 7420, board > 0914RT) by setting DELL0501 _STA to 0, but Dell has not shipped a > corrected BIOS for the 7410 even in the latest release (1.37.0, > 2026-05-28). > > Add a DMI quirk to force native backlight on this model so that i915 > registers intel_backlight and brightness control works out of the box. > > Tested on: > - OptiPlex AIO 7410 35W (01KP8D, BIOS 1.37.0) -- confirmed > acpi_backlight=native produces working intel_backlight (raw, > max=96000), DMI quirk has the same effect. > - OptiPlex AIO 7420 35W (0914RT, BIOS 1.27.0) -- DELL0501 absent in > updated BIOS, intel_backlight works natively (no regression). > > Signed-off-by: Chitransh Mandhaniya Thanks, patch looks good to me: Reviewed-by: Hans de Goede Regards, Hans > --- > drivers/acpi/video_detect.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c > index e3b69f876d24..1af14e04e597 100644 > --- a/drivers/acpi/video_detect.c > +++ b/drivers/acpi/video_detect.c > @@ -883,6 +883,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = { > DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7770 AIO"), > }, > }, > + { > + .callback = video_detect_force_native, > + /* Dell OptiPlex AIO 7410 35W */ > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), > + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex AIO 7410 35W"), > + }, > + }, > > /* > * Models which have nvidia-ec-wmi support, but should not use it.